The effects of periodic environmental enrichment at different life stages on the welfare and production of growing pigs
It is known that the welfare of intensively raised pigs is improved when housed in enriched versus barren conditions, however, the interaction between enrichment and different life stages is largely understudied. The current study evaluated the influence of periodic enrichment during different life stages on welfare and production in growing pigs. A total of 240 pigs were housed in either Control (C) or Enriched (E) environments during Early life (0-9 weeks of age). The enrichment used in the current study was loosely crumpled newsprint with an added functional neurosensory liquid solution (Phytozen®). Upon moving to grow-finish (GF) for the remainder of the trial (Late life: 10-21 weeks of age), half of the pigs changed environments while half remained in the original environment resulting in four treatments for this stage: CC, CE, EC and EE. Growth was measured throughout life. Post-mixing aggression was evaluated after weaning and when moving to GF. Tail bites and body lesions were assessed throughout GF. A subsample of pigs was transported to the abattoir and carcass characteristics were analyzed. Statistical analysis of Early and Late life data was done using mixed linear models. Growth was increased with enrichment between 18-21 weeks of age (P=0.011). Post-mixing lesions were reduced in E pigs compared to C at weaning (P<0.001 for front and hind regions). The number and severity of tail bites were reduced with the provision of enrichment throughout life (P=0.077 and 0.032, respectively). Lesions during GF were reduced with the provision of enrichment during Late life (CE and EE < EC and CC; P<0.001 for all body regions). Enrichment provided during Early life resulted in greater carcass weights and lean depth (P=0.040 and P=0.031, respectively). The current study provides evidence that periodic enrichment is an effective way of reducing damaging behaviours throughout life. It was shown that pigs with access to enrichment throughout life had improved welfare and behaviour compared to pigs in all other treatments.
Pigs, environmental enrichment, periodic enrichment, life stage, tail biting, damaging behaviours
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